Mercury tube electric circuit closer



June 23, 1936. I 'H W 2,044,882

MERCURY TUBE ELECTRIC CIRCUIT CLOSER Original Filed March 25, 1952 h INVENTOR ALFRED COLQUWT HOWARD ATTORNEY Patented June 23, 1936 UNITED STATES PATENT OFFICE MERCURY TUBE ELECTRIC CIRCUIT CLOSER Alfred Colquitt Howard, Beloit, Wis., assignor to E. and T. Fairbanks and Company, St. Johnsbury, Vt., a corporation of Vermont Original application March 25, 1932, Serial No.

601,148, now Patent No. 2,014,282, dated September 10, 1935. Divided and this application October 20, 1933, Serial No. 694,457

1 Claim. (Cl. 200-52) This invention relates to improvements in merwhich are level with the pivot 4, and the mercury cury tube electric circuit closers especially for tube l is also provided with an adjustable counuse in conjunction with the mercury tube inditerbalance weight l6. An indicator 1 is mounted cator control covered by my co-pending patent on the mercury tube I and co-operates with the 5 application Ser. No. 601,148, filed March 25, 1932, graduations of the chart 9, the Whole mechanism 5 of which this application is a division now Patent being enclosed in the housing H mounted on the No. 2,014,282 issued September 10, 1935. scale frame S.

The mercury tube indicator control referred to The mercury tube electric circuit closer is deprovides a structure consisting of one or more signed for co-operation with a mercury column pivotally mounted annular tubes carrying an in- 5 carried in an annular tube l as described in 10 dicator, being partially filled with mercury and the above referred to co-pending application, and forming a mercury column therein and adapted is adapted to control the operation of a, circuit thereby to dampen the oscillations of the indifor any special purpose desired, its operation cator. varying in accordance with the location of the Therefore, the primary object of the present contact members in the wall of the mercury tube 15 invention is to provide the mercury tube with l. The electric circuit closer comprises two electrical contact means designed to contact spaced, longitudinally adjustable contact memwith the ends of the column of mercury in the bers 25, each provided on the inner end with a tube and thereby energize an electrical circuit to depending, pointed contact tip 26, whereby each operate a solenoid or other electrical mechanism tip may be adjusted and positioned longitudinally 20 as may be desired. on the crest of each mercury column at the Another object is to provide the mercury tube proper point to insure synchronous co-action of with electrical spaced contact members extendthe opposed contact tips in closing the circuit at ing within the tube, adjustably mounted therein the proper moment. The outer end of each conand provided with means for locking the contact tact member 25 is provided with a threaded por- 25 members in their adjusted position. tion 21 inserted in a threaded opening 28 in an Still another object is to provide an insulated insulating member 29 mounted in a threaded mounting for the contact members adapted to opening 30 in the outer wall 3| of the metal co-operate with the adjusting and locking means. tube I. The insulating members 29 are provided 30 In the accompanying drawing there is illusfor adjusting purposes with a knurled cap 32 and 30 trated a preferred embodiment of the invention, knurled lock and adjusting nuts 33a and 33b in which, respectively, mounted on the outer end of the Figure 1 is a vertical elevation of the indicator contact members 25, which serve to secure and housing in position on the scale frame with the hold the contact members fixedly in position. If co-operating scale mechanism, showing the elecso desired, adjustable leveling screws 34 may be 35 tric circuit closer in the mercury tube, partly in used to adjust and maintain the housing H in a section, together with the electrical connections. level position.

Figure 2 is an enlarged fragmentary view of a The electric circuit comprises wires W attached part of Fig. 2 indicated by the arrow point, showto each contact member 25 and leading to a ciring the electric contact member and co-opercuit centralizing insulator platePmounted on the 40 ating parts. cross arm 2 and hence to the central insulator Figure 3 is an enlarged, fragmentary view on plate R attached to the housing H above the tube the line 33 of Fig. 1, showing the position of I. Wires W lead from the central insulator plate the mercury tube and its mounting. R to the battery or other source of electrical Figure 4 is a detached view in vertical section energy E and to an electric bell B, for example, 45 of the mercury tube electric circuit closer, show- While wires W lead to a manually operated bating the control as applied to the tube for operatery circuit switch T controlling the opening and tion at a particular position to close the circuit closing of the main circuit from the battery E. at that point. The contacts 25 may be placed in the tube I at In the drawing I designates an annular tubular any point above the surface 6 of the mercury 50 member made preferably of metal or other suitcolumn 5, as shown in Fig. 4, so as to function able material mounted on a cross-arm 2, integral at that particular point in closing the electrical therewith and mounted on a pivot 4 seated on a circuit and operating such electrically operated standard or support 3. The tube is partially filled mechanism as may be desired and hereinafter with mercury forming a column 5, the ends 6 of described. 55

In operating the mercury tube as an indicator control, when the beam Ed has been adjusted to weigh a given or predetermined weight, the mercury column 5 is adapted to flow around in the tube I as the indicator l and the tube 11 are turned in one direction or the other by the loop member [8 under the influence of the beam 2B in accordance with the load. As the proper weight of the load is reached with the consequent movement of the beam 28 to the balance or zero position the mercury column 5 gravitates to the under side of the tube 5, the indicator 7 returning to its balance or zero position, as shown in Figs. 1 and 4.

However, in the operation of the electric circuit closer, an exemplification of which as applied to an electric bell is illustrated in Fig. 1, the contact members 25 are arranged in contact with the upper surfaces 6 at each end of the mercury column 5, so that the bell will ring only when the indicator '3 comes. to rest at the balance position of zero and thus, for example, indicating to an" inspector or other ofiicial at a distance that the proper weight of the load has been placed on the scale.

The main battery circuit switch T is closed before the load is placed on the scale, thus closing the entire circuit. During the loading of the scale the indicator 1 moving to one side or other of the zero or balance position and the mercury column 5 flowing around in the tube l, so as to free one end of the mercury column 5 from contact with its co-operating contact member 25, will open the circuit, which will be held open until the indicator 7 reaches the zero or balance position as previously described.

In this particular arrangement for use in con nection with an over and under indicator (Fig. l) the contact members 25, it will be noted, are in contact at each end of the mercury column 5 when the circuit is closed and the indicator is at zero and open when the indicator goes to either side of zero. Thus when closed the electric circuit, which is entirely insulated from the metal parts co-operating with the tube, passes through the mercury column 5, which then acts as a connecting medium with the electric source during a weighing operation in accordance with the position of the ends 6 of the mercury column 5.

However, when the mercury tube electric circuit closer is used on certain types of dial scales for the purpose of operating at a particular weight indication or various weight indications of the scale indicator, so as to close the circuit and thus energize the desired electrically operated mechanism such, for example, as a magnetic switch or relay to produce a desired result, or to light a lamp or otherwise effect a signal for the particular indicator position. In this application of the invention, as shown in Fig. 4, one contact member 25 is located in the base of the tube l and the other contact member or members 25 may be located at the desired position or positions so as to close the circuit at those particular points and operate the electrically operated mechanism associated therewith.

While I have shown a preferred embodiment of my invention it is evident that modifications of the invention may be made that Will come within the scope of the invention and, therefore, I do not desire to limit the invention to the exact form of construction shown and described herein.

I claim:

In a mercury tube electric circuit closer, an annularly disposed tube provided with an indicator and a cross arm concentrically mounted around a pivotal point of support, the tube being partially filled with mercury forming a mercury column therein and constituting connecting means with a source of electrical energy adapted to operate electric mechanism in circuit therewith, circuit closing means adapted to provide synchronous co -action of spaced longitudinally adjustable contact members disposed in the said electrical circuit and extending within the mercury tube and connected with the said circuit, one contact member being in contact with the mercury column and the other contact member moving with the tube until it contacts with an end of the mercury column to close the electrical circuit and thus operate the said electric mechanism, and a depending pointed contact tip on each contact member held in adjusted position by the contact member and adapted to engage the crest of the co-operating mercury column and 7 thus close the circuit at the proper moment.

ALFRED COLQUITT HOWARD. 

